India generates about 60 million tonnes of trash every year. Ten million tonnes of garbage is generated in just the metropolitan cities: Delhi, Mumbai, Chennai, Hyderabad, Bangalore and Kolkata.
The landfills of most of these cities are already overflowing, with no space to accommodate fresh garbage waste.
According to an expert at the Centre of Science and Environment, instead of constructing new landfill sites, the government should be looking into innovative methods to dispose and recycle its waste. The reason why most landfill sites are over-flowing is because the current waste disposal system is flawed.
“The segregation of biodegradable waste from non-biodegradable waste is not done properly,” said Sunita Narain, director of the Centre of Science and Environment. “The municipal authorities should develop a model to ensure the same.”
In addition, at many landfill sites due to the lack of an effective waste recycling system, solid waste is burned without segregating bio-degradable waste from non-biodegradable waste. This leads to the release of toxic gases that cause acute respiratory diseases and environmental degradation.
More landfill sites
Delhi generates approximately 9,000 metric tonnes of solid waste, which is dumped into four landfill sites. Three of the four landfills in Delhi should have stopped being used between 2005 and 2009. Experts say this is not unusual.
In addition, Delhi’s four landfill sites extend over 164 acres, when the current requirement is nearly four times the available area – 650 acres, according to a 2011 report by the Central Pollution Control Board.
“Even if people learn to dump their garbage at the dhalaos [a small garbage dump typically servicing a few streets of a neighbourhood], how will that help if the dhalaos can’t be emptied, since there are barely any space left in landfills,” Narain asked.
Mumbai generates 6,500 metric tonnes of garbage daily, including 2,500 metric tonnes of silt and debris, besides 25 tonnes of bio-medical waste. A significant amount of the waste (4,500 metric tonnes per day) is dumped at the Deonar dumping ground, located in the eastern suburb of the city.
According to Brihanmumbai Municipal Corporation, the Deonar landfill site will expire by the end of 2016. The landfills in Gorai and Chincholi Bunder have already been shut down due to over-use. The Mulund dumping ground has also been overused and the BMC is contemplating shutting this down as well.
In addition, Mumbai also generates 21 lakh tonnes of industrial waste per year, which is half of the national total, according to the Central Pollution Control Board report. Industrial waste is also dumped into the landfills.
Segregation and recycling of waste
Segregation of waste should occur at the colony or neighbourhood level, when the waste is collected. The dhaloas in the metropolitan cities are always overflowing due to lack of segregation. Recyclable waste like construction and demolition waste, organic waste like household garbage, toxic waste like medical waste, are all mixed together.
“Most of the construction and demolition waste can be recycled,” said Ravi Agarwal, director at Toxics Link. “It shouldn’t reach the landfills to begin with. The municipal bodies should learn from countries abroad that recycle most of their C&D waste.”
“We cannot quantify the amount of organic waste reaching us because it's all mixed,” a South Delhi Municipal Corporation official said. Once mixed, it is impossible to segregate recyclable waste from organic waste, according to Agarwal.
Nearly 20% of methane gas emissions in India is caused by landfills. Travel past one of these landfills and you are bound to see great spirals of smoke climbing the horizon, as the trash catches fire due to the heat generated by the decomposition of waste.
Most of these landfills have not been built according to accepted specifications. “Due to the decomposition of inorganic waste, the ground water is contaminated," Agarwal said. "There is also the problem of leachate [when rainfall percolates through the waste in a landfill] because most of these dumping grounds are not scientific landfills.”
A study by scientists at the School of Environmental Sciences in Jawaharlal Nehru University found high levels of nickel, zinc, arsenic, lead, chromium and other metals in the solid waste at landfills in metro cities, especially in Delhi.
“Before cleaning up the city, the government needs to sort out a concrete waste management system that ensures segregation and recycling,” Narain said. “Process everything that can be processed and dump only the residue or inerts in the landfill.”